An attractive application of semi-transparent photovoltaic (PV) solar cells is the possibility to use them in building integrated elements that can lead to self-sustaining buildings at low cost. Organic and inorganic materials have been widely used for the development of semi-transparent solar cells and have been suggested for integration in office buildings and replacement windows. This integration offers harvesting of solar energy over wider surfaces.
Thus far, there are only a few reports about the development of semi-transparent perovskite solar cells. Eperon et al [1] used a strategy which relied on de-wetting of a perovskite film to create ‘perovskite islands’; thus achieving high transmittance while decreasing the overall PCE due to the voids within the active layer. Moreover, it seems that with this method it is difficult to precisely control the transparency of the cell.
In other reports [2,3], a thin perovskite layer was deposited by evaporation. However, evaporation-based processes are very costly, require high capital investments, and are very complicated for up-scaling, which is required for industrial applications. In addition, the evaporation technique, using only a thin film of the absorber material in the solar cell (i.e. the perovskite) leads to a decrease of the overall solar cell efficiency.